The present disclosure relates to electronic circuits and methods, and in particular, to slew rate control boost circuits and methods.
Amplifier circuits are a basic building block on modern electronics. Amplifiers typically receive an input signal and amplify a voltage or current, for example. Such amplifiers are typically constructed from various arrangements of transistors, including bipolar transistors and/or metal oxide semiconductor (MOS) transistors. One common problem with transistor amplifiers pertains to distortion. As signals are processed in the various transistors, asymmetries between devices and a variety of other factors cause the processed signals to be altered. For audio applications, for example, reducing distortion is particularly important.
One factor that can cause distortion is slew rate. Voltage slew rate is a term that refers to the ability of an amplifier to change between a high voltage and a low voltage on a particular node. In some situations, design of an amplifier may lead to asymmetric slew rate, where a positive slew (from a low voltage to a high voltage) occurs at a different rate than a negative slew (from a high voltage to a low voltage). Asymmetry in the slew rate can lead to unwanted distortion.